Sintering machine apparatus



June 9, 1959 R. A. POWELL.

SINTERING ,MACHINE APPARATUS Filed March 1, 1957 United States Patent O2,890,038 SINTERING MACHINE APPARATUS Russell A. Powell, Pittsburgh,Pa., assignor to Koppers Company, Inc., a corporation of DelawareApplication March 1, 1957, Serial No. 643,268 '2 Claims. (Cl. 266-21)The present invention relates to sintering machine apparatus and moreparticularly to a windbox-exhaust main arrangement for sintering machineapparatus.

In the past, sintering machine apparatus has included a windbox-exhaustmain arrangement wherein downleg ducts connecting the windboxes to theexhaust main have entered the exhaust main at the upper portion of themain. As a result, dust particles which have been entrained in theinduced draft as it passes through the bed of material being sinteredmust necessarily travel downwardly through the main stream of theexhaust to be dropped out. A large portion of these particles intendedfor hoppers positioned below the exhaust main never reach the hoppersbut instead are carried along with the main stream of the exhaust toplace an additional load on the mechanical or electrical collectorspositioned at the downstream end of the main. Further, with the downlegducts arranged to enter at the upper portion of the main, it has beennecessary to provide each of these duets with an elbow joint so that theoverall arrangement would not require unwarranted heights inconstruction. These elbow joints have presented a ready area of wearsince the dust particles entrained in the induced gas stream impingeagainst the joints in their flow downwardly to the exhaust main.

The present invention, recognizing these many disadvantages of pastpractices, provides a windbox-exhaust main arrangement which eliminatesthe elbow joints for the downleg ducts to reduce installation andmaintenance costs and to provide a compact arrangement which can behoused in buildings of minimum height. In addition, the presentinvention provides an exhaust main arrangement which permits a maximumdropping out of dust particles from the induced stream into the exhaustmain hoppers to greatly reduce the load on mechanical and/or electricalcollectors positioned at the downstream end of the exhaust main and toincrease the dust collecting efiiciency of the exhaust main hoppers.

Various other features of the present invention will become obvious toone skilled in the art upon reading the disclosure set forthhereinafter.

More particularly, the present invention provides, in a continuoussintering machine arrangement, conveyor means for supporting a travelingbed of material to be sintered, Windbox means associated with suchconveyor means to induce a draft through the bed of material, an exhaustmain spaced from the conveyor means, and duct means extending in asubstantially straight line between and connecting such windbox meansand the exhaust main, the duct means being connected to the lowerportion of the exhaust main so that a maximum dropping out of dustparticles which have been entrained in the induced draft is accomplishedin the exhaust main.

It is to be understood that various changes can be made by one skilledin the art in the arrangement, form, and construction of the severalparts of the structure set forth hereinafter without departing from thescope or spirit of this invention.

2,890,038 Patented June 9, '1959 Referring to the drawings,

Figure 1 is a partially broken-away schematic elevational view of asintering machine arrangement which incorporates one advantageousembodiment of the wind box-exhaust main arrangement of the presentinvention;

Figure 2 is a sectional view taken in a plane passing through line 2-2of Figure 1.

As can be seen in Figure l of the schematic drawings, a main building 2is provided to house the sintering machine apparatus which can be of thecontinuous type and which incorporates endless conveyor means broadlydesignated by reference numeral 3, the endless conveyor means having anupper run 4 and a lower run 6. Positioned in series below the upper runof the conveyor are a plurality of windboxes 7, these windboxes servingto accommodate the draft induced through the bed of material to besintered as it passes over the upper run 4 of the endless conveyor. Itis to be noted that the structure disclosed is only schematic and thatcomponents such as the pallet train, ignition hood, and grate bars, allwell known in sintering machine apparatus, can be of various types inaccordance with the results desired.

Positioned to the side of and below the windboxes 7 in spaced relationtherefrom is the exhaust main 8. In the advantageous embodiment of theinvention disclosed, exhaust main 8 has a trapezoidal contour,increasing progressively upward in cross-sectional area toward its existend with its bottom side in a plane parallel to the ground level of thesintering machine apparatus. The progressive increase in cross-sectionalarea toward the exit end of the main provides for the increase in volumeof induced gases which the main necessarily must accommodate as thedownstream end thereof is approached.

As can be seen more fully in Figure 2 of the drawings, windboxes 7 areconnected by downleg ducts 9 which, in the advantageous embodiment ofthe structure disclosed, are cylindrical in shape and which providesubstantially straight line connections between the windboxes and theexhaust main. With such straight line duct connections, the elbow jointsof the past and the wearing difficulties associated therewith areavoided, as has been pointed out above.

Each of the ducts 9 connects to the exhaust main 8 at the lower side ofthe exhaust main 8 and, as a result, a maximum dropping out of dustparticles from the induced draft into the exhaust main is obtained,these particles falling into hoppers 11 positioned below the main 8 tobe carried away by endless conveyor 13. Thus, when the induced draftreaches collectors 12, which collectors are shown schematically asmechanical ones in Figure l but which also can be of the electricaltype, the dust loads on these collectors is greatly reduced.

With the structure abovedescribed, a windbox-exhaust main arrangement isprovided which is inexpensive to install and maintain and which providesfor maximum operation of the collecting hoppers positioned below theexhaust main and the precipitators positioned at the downstream end ofthe main.

The invention claimed is:

1. In a continuous sintering machine, a conveyor for supporting a bed ofmaterial to be sintered, a plurality of wind boxes associated with saidconveyor for inducing a draft through the bed of material, an exhaustmain having a bottom section opening into the tops of a plurality ofopen-ended hoppers depending therefrom, a top and side walls, said mainbeing located Wholly to one side of said conveyor, and a plurality ofsubstantially unidirectional straight ducts, said ducts being connectedat one end to one side wall of said exhaust main adjacent the bottomthereof and directed across the upper portions of said hoppers and eachbeing connected at its other end to a respective one of said wind boxes,

whereby-the maximum of the dust particles are discharged into said,hoppers.

2. In a continuous sintering machine, an endless conveyor having anupper and lower run, said upper run being arranged to support atraveling bed of material to be si-ntercd, a plurality of wind boxespositioned below said upper run, an exhaust main having a bottom sectionopening into the tops of a plurality of open-ended hoppers dependingtherefrom, a top and side Walls, said main being located wholly to oneside of said conveyor and having its bottom wall disposed below saidlower run and said top being inclined relative to said conveyor so thata portion thereof adjacent the exit end of said main extends above saidlower run, and a plurality of equal -4 7 length and substantiallyunidirectional straight ducts, each of said .ducts being connected atoneend to one sidewall of said exhaust main adjacent the bottom thereof anddirected across the upper portions of said hoppers and each beingconnected at its other end to a respective one of said wind boxes.

References Cited in the file of this patent UNITED STATES PATENTSShallock Sept. 2, 1941 2,498,766 Pettigrew Feb. 28, 1950 2,768,890 CoverOct. 30, 1956

